Thomas Midgley

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Thomas Midgley, Jr. (born May 18, 1889 in Beaver Falls , Pennsylvania , † November 2, 1944 in Worthington , Ohio ) was an American mechanical engineer who worked as a chemist . He developed both the petrol additive tetraethyl lead and the chlorofluorocarbons (CFCs). At the time of his discoveries, his merits were praised; today his legacy is viewed in a much more nuanced way. The historian John Robert McNeill remarked that Midgley "had more impact on the atmosphere than any other organism in Earth history."

education

Midgley attended Betts Academy in Stamford from 1905 in preparation for college . This was followed by a degree in mechanical engineering at Cornell University .

plant

Sign on a gas pump advertising tetraethyl lead. The correct English term tetraethyl lead has been shortened to ethyl so that the term lead does not appear on the pump.

While working for General Motors , he discovered that leaded gasoline prevents " knocking " in internal combustion engines . Initially, this discovery was hailed as a major technical advance and tetraethyl lead became a standard additive in gasoline. It was only later that it became clear that this would release large amounts of lead into the atmosphere , causing health problems all over the world. Workers who produced the additive were much more severely affected. There were several deaths and severe nerve damage with gait disorders and delusions among the workers. After inhaling the vapor of his fuel to demonstrate its harmlessness, Midgley got lead poisoning in 1924, which he had to cure for over a year.

As part of his research on tetraethyl lead, he developed a process for extracting bromine from seawater. This was necessary for the use of tetraethyl lead in internal combustion engines (see also tetraethyl lead and 1,2-dibromoethane ) .

His second discovery, CFC, was introduced to make refrigerators safe; by synthesizing chlorofluorocarbons (also called freons ) to replace the many toxic or explosive substances that had been used until then. Here, too, Midgley did not shy away from taking personal risks to underpin the importance of his development: at a demonstration in front of the American Chemical Society in 1930, he inhaled a lung full of dichlorofluoromethane and blew out a candle with it just to show that its gas is both non-flammable and harmless. Indeed, CFCs are largely non-toxic to biological organisms. The problem associated with CFCs is that CFCs are extremely durable, can rise into the upper atmosphere and are chemically split there by solar radiation. The CFC decomposition products in turn lead to the breakdown of the ozone layer, which normally intercepts the high-energy solar radiation.

Aerosols have been one of the main uses of CFCs as an inert , safe propellant , from metered dose inhalers (asthma inhalers) to deodorants . Since the adoption of the Montreal Protocol , in which major countries agreed not to continue producing CFCs, health services and pharmaceutical companies have replaced these inhalers with non-CFC-based ones and trained patients in their use. The manufacture of CFCs is banned in industrialized countries.

Another great work was his research on rubber.

Thomas Midgley Jr. held over 170 patents . At the age of 51, he developed polio , which led to severe disabilities. To solve this problem, he designed an ingenious system of cords and pulleys that would lift him out of bed and into the wheelchair. He died at the age of 55 when he accidentally got tangled and strangled in the ropes of this device. Other sources suspect a suicide behind the alleged accident.

Business activity

Thomas Midgley was not only an outstanding researcher but also a businessman.

Since the founding of the Ethyl Corporation (manufacturer of tetraethyl lead), he has been its vice president and first general manager.

He was also Vice President of Kinetic Chemicals (maker of Freon ) and a Director of Ethyl-Dow Chemical Company (extraction of bromine from seawater).

Awards

Thomas Midgley received several high-profile awards:

Patents

literature

Web links

Individual evidence

  1. ^ Die kleine Enzyklopädie , Encyclios-Verlag, Zurich, 1950, Volume 2, p. 166.
  2. ^ John Robert McNeill , Something New Under the Sun: An Environmental History of the Twentieth-Century World (2001) New York: Norton, xxvi, 421 pp. (as reviewed in the Journal of Political Ecology )
  3. ↑ a b c d e f g h i Charles F. Kettering: Biographical memoir of Thomas Midgley, Jr., 1889-1944 (PDF; 943 kB). In: Biographical Memoirs, National Academy of Sciences 24, 1947, pp. 361-380.
  4. ↑ Carmen Giunta: Thomas Midgley, Jr., and the invention of chlorofluorocarbon refrigerants: it ain't necessarily so (PDF; 717 kB). In: Bulletin for the History of Chemistry Vol. 31, No. 2, 2006, pp. 66-74.
  5. ↑ Nichols medalists on the New York Section of the American Chemical Society, accessed April 15, 2015.
  6. ^ Franklin Laureate Database - Edward Longstreth Medal 1925 Laureates . Franklin Institute . Retrieved December 4, 2015.
personal data
SURNAME Midgley, Thomas
ALTERNATIVE NAMES Midgley, Thomas Jr.
BRIEF DESCRIPTION American engineer who developed the gasoline additive tetraethyl lead and chlorofluorocarbons (CFCs)
DATE OF BIRTH May 18, 1889
PLACE OF BIRTH Beaver Falls
DATE OF DEATH November 2, 1944
Place of death Worthington